Field
Various aspects of the present disclosure relate to wireless communications and, more particularly, to methods, apparatuses, and systems for reestablishing radio communication links due to radio link failure for user equipment that transmits data over a control plane.
Background
Wireless communication systems are widely deployed to provide various telecommunication services such as telephony, video, data, messaging, and broadcasts. Typical wireless communication systems may employ multiple-access technologies capable of supporting communication with multiple users by sharing available system resources (e.g., bandwidth, transmit power). Examples of such multiple-access technologies include code division multiple access (CDMA) systems, time division multiple access (TDMA) systems, frequency division multiple access (TDMA) systems, orthogonal frequency division multiple access (OFDMA) systems, single-carrier frequency divisional multiple access (SC-FDMA) systems, and time division synchronous code division multiple access (TD-SCDMA) systems.
These multiple access technologies have been adopted in various telecommunication standards to provide a common protocol that enables different wireless devices to communicate on a municipal, national, regional, and even global level. An example of an emerging telecommunication standard is Long Term Evolution (LTE). LTE is a set of enhancements to the Universal Mobile Telecommunications System (UMTS) mobile standard promulgated by Third Generation Partnership Project (3GPP). It is designed to better support mobile broadband Internet access by improving spectral efficiency, lower costs, improve services, make use of new spectrum, and better integrate with other open standards using OFDMA on the downlink (DL), SC-FDMA on the uplink (UL), and multiple-input multiple-output (MIMO) antenna technology. However, as the demand for mobile broadband access continues to increase, there exists a need for further improvements in LTE technology. Preferably, these improvements should be applicable to other multi-access technologies and the telecommunication standards that employ these technologies.
In LTE, a Radio Link Failure (RLF) procedure allows a user equipment (UE) to move a radio communication link (e.g., radio communication connection) from a first radio access node (e.g., a cell on an evolved node B (eNB)) to a second radio access node without having to go through idle to active states in the event the radio communication link with the first radio access node fails. Ordinarily the messages from the UE to the second radio access node are secured/protected using access stratum keys to ensure that a rogue/attacker UE does not maliciously attempt to disconnect a genuine UE from an established radio communication link by initiating an improper RLF procedure with another radio access node on behalf of the genuine UE. However, certain UEs utilize the control plane (e.g., non-access stratum (NAS)) to transmit user plane data without establishing a security association (or security context/keys) with a radio access node. In such a case, those UEs cannot secure or protect messages for radio link reestablishment due to RLFs with a target radio access node because the target radio access node does not have or cannot obtain the access stratum (AS) keys.
Consequently, there is a need for methods, devices, and systems to secure and protect the radio link reestablishment procedure from malicious attacks when such a UE experiences RLF. These methods, devices, and systems may be utilized in schemes where the UE uses the control plane signaling with a network node to transmit user plane data (e.g., NarrowBand Internet-of-things (NB-IoT) UEs).